Introducing water mist know-how – Part 2

Water mist expertise remains to be a comparatively new concept in phrases of fire suppression, yet it is proving to be an exciting development within the industry. As the industry evolves, so do the rules, laws and requirements to have the ability to improve safety and enable growth. These can differ largely from country to country, and even area to area.
The method in which a water mist system operates is an analogous mechanism to the traditional sprinkler system in that the nozzles are normally activated via a bulb which blows at a particular temperature allowing for the activation of the mist through a low-pressure water piping system.
Here we take a look at how some water mist nozzles are produced and installed – from arriving as a big ‘bar’ of metal, to becoming the environment friendly water mist nozzles we see put in in plenty of new projects/developments throughout much of the globe at present.
The metallic arrives for chopping
Here at Dual Mist Ltd, Stainless Steel 304 is used for a lot of parts as it is extremely sturdy and corrosion resistant in comparison to different comparable metals. The body is machined out of Brass CZ121, which arrives as massive bars of steel which might be delivered to the warehouse in 3m lengths. This is then minimize into two smaller components ready to insert into the machine. Not all water mist companies have the power to machine the elements they require in-house though it could possibly prove very helpful for value and manufacturing purposes as we’re about to see.
Machining
The steel is fed to a Nakamura WT150 CNC lathe. This high-performance Japanese machine device is provided with carbide tooling and high-pressure by way of coolant techniques, with the twin-spindle and twin-turret making haste of the otherwise complicated parts. A Citizen M532 Sliding Head Lathe is used for the smaller parts.
A Citizen L12 additionally makes the filters with a functionality of drilling 365 holes in 51 seconds, utterly automated – this means it might possibly turnover an unbelievable 4,000 filters in a weekend completely unmanned.
The brass heads are also de-burred on the machine, removing all sharp edges earlier than being polished and despatched for Electroless Nickel Plating. This offers a corrosion-proof coating to the brass, enabling it to turn out to be far more durable. All elements are then inspected for dimensional accuracy before the assembly stage.
This Technifor Laser machine engraves every nozzle in preparation for the testing phases.
Assembly
There are many small components of assorted shapes and sizes that make up the nozzle – In the DM4R nozzle, (as seen on the leak-testing pic) there are a complete of thirteen elements or ‘components’. These parts are then meticulously put collectively and assembled by the production team requiring a fair quantity of labour before the ultimate product is achieved. Various stages embrace tightening with specially adapted instruments, pressing using a hand-press and utilizing a selected ‘Locktite’ formulation at some phases which is a threadlock that forestalls fixings from coming loose during the operational lifetime of the product. The final stage of assembly is carefully loading the bulb and applying the right load to it using a torque wrench.
The assembled nozzles are then positioned on another machine to find a way to be labelled and uniquely identified using a serial number. At Dual Mist Ltd that is done on a Technifor Laser Engraver fitted with a 4th axis unit before they are ready to be placed via the assorted stages of testing.
Testing
Cull Testing
Also often recognized as bubble testing in layman’s phrases, this check is to ensure no harm has occurred to the bulb throughout assembly and is a crucial test for LPCB approval. The take a look at includes using a high-powered microscope to measure the scale of the bubble in each bulb earlier than placing in heat water in order to shrink the dimensions of the bubble to nothing. Once this is checked, the nozzles are then left to relaxation and return to room temperature earlier than the bubble is measured as soon as again so as to ensure it has returned to the unique measurement inside a small tolerance.
Leak Testing
Every nozzle is also stringently tested for leaks by applying 24-bar pressure for 1 hour and guaranteeing no water has escaped. It is uncommon for any leaks on the production line, but this is an extremely vital stage of the testing as leaks could occur if filth is trapped within the seal face.
Activation Testing
On a month-to-month foundation, random nozzles are also tested for activation by inserting the nozzle on a stress jig at various pressures and applying heat to the bulbs. The nozzles should all activate cleanly throughout the entire pressure vary specified to that nozzle.
A member of the manufacturing staff uses a microscope and software to discover out the dimensions of each bubble within the bulb.
Approvals
At Dual Mist Ltd, these checks are not just to assure the standard of the production line but are also an essential a half of the LPCB Approval. These approvals allow customers to recognise that the merchandise they’re shopping for are made to the best potential high quality normal in the area.
เกจวัดแรงดันไทวัสดุ to that is that the Approval Testing system could be both costly and time-consuming – generally needing to be booked a number of months upfront and requiring years of onerous work to attain.
The nozzles produced by Dual Mist have been put through their paces at BRE Global in phrases of each hearth testing and component/type approval.
Tamper proofing
In order to make sure that no person is tempted to intervene with the grub screw holding the bulb, a small plastic bung is pressed into the grub screw. The stress load setting on the bulb is then subsequently fastened.
The nozzles are then able to be packaged and despatched off for set up.
Here is an example of a control panel having been installed in The Claridges Hotel, London, UK. This is where the system is operated.
Installation
Rather than having to use the heavy and labour-intensive metallic pipes often utilized in high-pressure techniques, low-pressure water methods can use CPVC piping. This is a special kind of fire-resistant plastic enabling quick set up. Instead of threading each pipe, a heated glue can be utilized to rapidly build large pipe networks. These networks are accredited to handle as much as 12 bar strain. The nozzles are screwed into a special pipe adaptor utilizing a half-inch fuel fitting.
An electrical control panel is fitted for the system management together with pumps and a water tank, often with a mains feed.
The system is examined, signed off and handed over to the consumer.
The last product as soon as installed. This reveals how we expect to see the nozzles once a venture has been completed.
Conclusion
As we will see there are numerous levels to go from metal to nozzle head with each nozzle taking a big effort by numerous professionals to complete to the permitted normal.
Not solely do water mist nozzles require a number of phases of machining and assembling, they want to also undergo a string of tests to find a way to be accredited for set up. Once put in, there are even further tests undergone, typically by third-party organisations to ensure that the whole fire suppression system to finally be handed over to the shopper.
Water mist expertise assures safety, quality and assurance via the stringent testing that is required.
With the current publication of water mist requirements, notably in Britain over latest years, constructing builders can now be assured that the standard required for water mist systems is now at an equivalent commonplace to other suppression methods.
For extra information, go to www.dualmist.com
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